Upload image to facebook using graph api in PHP - php

Question

I'm trying to upload an image to facebook using graph api. I want to submit the image as a file instead of providing a URL which is another option. I'm using PHP Laravel and guzzle to achieve this. Unfortunately when I upload the file I'm getting an error which would seem to indicate that the image is not recognised.
This is the documentation I am using
https://developers.facebook.com/docs/graph-api/reference/page/photos/#publish
This is my error message
message: "Client error: `POST https://graph.facebook.com/v12.0/99999999999/photos` resulted in a `400 Bad Request` response:\n{\"error\":{\"message\":\"(#324) Requires upload file\",\"type\":\"OAuthException\",\"code\":324,\"fbtrace_id\":\"ACxilINTWYdb3wGOXfGg7 (truncated...)\n"
Here is my code
public function media(Request $request)
{
$facebookPageConnection = FacebookPageConnection::find(2);
$file = $request->file('file');
$client = new Client();
$body = $client->post("https://graph.facebook.com/v12.0/$facebookPageConnection->facebook_page_id/photos", [
'multipart' => [
[
'name' => 'message',
'contents' => 'test post'
],
[
'name' => 'source',
'contents' => base64_encode(file_get_contents($file))
],
[
'name' => 'access_token',
'contents' => $facebookPageConnection->access_token
]
]
])->getBody();
return json_decode($body);
}

Answer 1

My mistake was to use
file_get_contents
and
base64_encode
Instead to get it to work I needed to use fopen
$body = $client->post("https://graph.facebook.com/v12.0/$facebookPageConnection->facebook_page_id/photos", [
'multipart' => [
[
'name' => 'message',
'contents' => 'test post'
],
[
'name' => 'source',
'contents' => fopen($file, 'rb')
],
[
'name' => 'access_token',
'contents' => $facebookPageConnection->access_token
]
]
])->getBody();